High-tech drive control performance under supply voltage deviation from required quality

High-tech drive control needs high quality of electrical energy like safe, continuous voltage supply with the required current at constant rms values and at constant frequency, then pure sinusoid waveform of voltage. If the rated voltage impressed to the computers in control systems will be decreasing to its 75% the disturbance in their operation appears and at 50% they all will loose their ability for work. If tested computers are working only in a room, then the total harmonic distortion was 3.47%. When fluorescent light sources were also working there the distortion increased up to 4.71% and when welding equipment were added the distortion went up to 10.98%. If it exceeds 10% then the acquired data, commands, control signals will be lost, thus re-installation or even repair is needed for the computers. All in one, drive control performance will be poor or getting near to zero if supply voltage quality does not meet the requirements.